This invention relates to a method and apparatus for separating particulate material from hot gas, commonly known as a cyclone separator system.
With the gradual advent of extremely demanding legislation for protection of the atmosphere, the field of particle separation from gases has acquired a very high priority, and there has been an ever-increasing need for improved efficiency and durability of the separating equipment, and particularly for separating out more and more of the finer particles.
In the past the prevailing approach has been to feed the particulate laden hot gas radially into a cylindrical barrel so as to cause a vortical flow of the gas and particles. As shown in the present disclosure, it has now been recognized that the energy imparted to the particles prior to arrival at the inlet of the system can be better utilized by dispensing with the vortical flow and projecting the particles directly toward the system outlet so that, by virtue of this momentum, a very substantial portion of the particles will be carried beyond the separators and thus separated in a different way from the gas in which it has been entrained.
This concept of direct separation introduces new complexity into the already severe challenge of dealing with special heat expansion problems characteristic of cyclone separation systems as a class. A wide variety of temperature conditions are encountered from startup to normal operating temperatures, including short term over-temperature excursions of several hundred degrees Fahrenheit. These severe temperature changes can result in rather extensive movement of individual parts. In addition to the thermal load, the particulate laden gas is introduced under pressure, and one must also take into account vessel pressure and another form commonly known as "collapsing pressure" due to pressure loss through the cyclone system.
In addition, from time to time special pressure-temperature-velocity conditions may arise which set up violent oscillation of heavier parts. If very special measures are not taken to compensate for these destructive forces, they will quickly take a toll on the efficiency and useful life of the entire structure.
The present invention takes these needs into account in a very special way.